In a sense, privacy is a medium, like air; we live within its embrace, to varying degrees, from our earliest days until our last. Its existence allows us to negotiate and contextualize our political and personal connections—in our relationship with the state as citizens, and with each other in our day-to-day dealings. It is a barrier that mediates the extent to which each of us is known or unknown to those around us.
Moreover, like the air itself, we rarely see privacy, or its value, clearly. As Jerome observed, it takes a mountain view to confirm the existence of air, by providing a perspective that forces us to account for it.1 Similarly, statutes, judicial rulings, and technological and commercial innovations implicating privacy each allow us a perspective on the extent to which we actually control information about ourselves. Such are the benchmarks that Igo has selected to chart the...